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chemistry

Microbead

Microbead is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Microbead rather than just read about it. In short: Microbeads are manufactured solid plastic particles of less than one millimeter in their largest dimension. They are most frequently made of polyethylene but can be of other petrochemical plastics such as polypropylene and polystyrene.

Microbead — main illustration
Microbead — illustration

Key takeaways

  • Microbead belongs to chemistry; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Microbead to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Microbead from memory before moving on to harder problems.

Reference excerpt

Microbeads are manufactured solid plastic particles of less than one millimeter in their largest dimension. They are most frequently made of polyethylene but can be of other petrochemical plastics such as polypropylene and polystyrene. They are used in exfoliating personal care products, toothpastes, and in biomedical and health-science research. Microbeads can cause plastic particle water pollution and pose an environmental hazard for aquatic animals in freshwater and ocean water. In the United States, the Microbead-Free Waters Act of 2015 phased out microbeads in rinse-off cosmetics by July 2017. Several other countries have also banned microbeads from rinse-off cosmetics, including Canada, France, New Zealand, South Korea, Sweden, Taiwan, and the United Kingdom.

Types

Microbeads are manufactured solid plastic particles of less than one millimeter in their largest dimension when they are first created, and are typically created using material such as polyethylene (PE), polyethylene terephthalate (PET), nylon (PA), polypropylene (PP), and polymethyl methacrylate (PMMA). The most frequently used materials are polyethylene or other petrochemical plastics such as polypropylene and polystyrene. Microbeads are commercially available in particle sizes from 10 micrometres (0.00039 in) to 1 millimetre (0.039 in). Low melting temperature and fast phase transitions make them especially suitable for creating porous structures in ceramics and other materials.

Regional differences The parameters for what qualifies as a microbead change subtly based on location and the corresponding legal jurisdiction; minor distinctions in the definition may be encountered from one country to another. For example, the U.S. official definition for a microbead, as per the Microbead-Free Waters Act 2015 laid out by Congress, is "any solid plastic particle less than 5 millimeters in size that was created with the intention of being used to exfoliate or cleanse the human body." On the other hand, Environment and Climate Change Canada (ECCC), the governmental agency responsible for Canada's microbead ban, settled on a definition which includes only plastics with diameters between 0.5 microns and 2 millimeters; although a diameter range of 0.1 microns to 5 millimeters was initially proposed, the definition was revised after consultation with members of industry and meeting resistance from plastic manufacturers who claimed that many of their raw materials (for example, those needed to make bottles for soft drinks) would be covered by the ban, affecting their business unduly. While the intent clause in the American law leaves open a loophole for producers of other equally frivolous and environmentally destructive products to potentially exploit in the future—as long as their use case does not involve grooming or personal care—the Canadian law has already been criticized publicly for its overly restrictive nature, which could cripple its efficacy in practice; in response to the revised definition, concerned conservation groups (including the Sierra Club of Canada) have raised warnings about the law's wording, fearing that Canada may "become a dumping ground for [those] microbead-containing products" which are now banned in the United States.

Use Microbeads are added as an exfoliating agent to cosmetics and personal care products, such as soap, facial scrub, and toothpastes. They may be added to over-the-counter drugs to make them easier to swallow. In biomedical and health science research, microbeads are used in microscopy techniques, fluid visualization, fluid flow analysis, and process troubleshooting. Sphericity and particle size uniformity create a ball-bearing effect in creams and lotions, resulting in a silky texture and spreadability. Smoothness and roundness can provide lubrication. Colored microspheres add visual appeal to cosmetic products.

Environmental effects When microbeads are washed down the drain, they may subsequently pass unfiltered through sewage treatment plants and make their way into rivers and canals, resulting in plastic particle water pollution. The beads can absorb and concentrate pollutants like pesticides and polycyclic hydrocarbons. Microbeads have been found to pollute the Great Lakes in high concentrations, particularly Lake Erie. A study from the State University of New York, found anywhere from 1,500 to 1.1 million microbeads per square mile on the surface of the Great Lakes. One study suggested that environmentally relevant levels of polyethylene microbeads had no impact on larvae. Some wastewater treatment plants (WWTPs) in the U.S. and Europe can remove microbeads with an efficiency of greater than 98%, others may not. As such, other sources of microplastic pollution (e.g. microfibers/fibers and car tires) are more likely to be associated with environmental hazards. A variety of wildlife, from insect larvae, small fish, amphibians and turtles to birds and larger mammals, mistake microbeads for their food source. This ingestion of plastics introduces the potential for toxicity not only to these animals but to other species higher in the food chain. Harmful chemicals thus transferred can include hydrophobic pollutants that collect on the surface of the water such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), and polycyclic aromatic hydrocarbons (PAHs). Because the negative impacts of microbeads are a recent discovery, there is still debate about the extent to which they harm various marine life. Despite this uncertainty in the scientific community, there is widespread consensus that microbeads are harmful to marine life. Current methods for cleaning microplastics from the ocean are inefficient, unscalable, and economically infeasible, which serves to intensify the harms they pose. Because their lifespan cannot easily be reduced, the current best method to reduce pollution is to invest in their prohibition.

Banning production and sale in cosmetics

… excerpt ends here. Continue reading the full article.

Illustrations

Microbead: Microbead legislation around the world
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Microbead legislation around the world .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{}  Full ban
Microbead: A microbead imaged using scanning electron microscopy
A microbead imaged using scanning electron microscopy

Worked examples

Example 1 — a first encounter with Microbead

Start with the simplest possible case. Write down what Microbead claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Microbead before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Microbead ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Microbead

In research
Microbead appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Microbead in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Microbead is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cosmetics chemicals, Plastics industry, so understanding it makes those chapters shorter.
In everyday life
Look for Microbead outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Microbead in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Microbead means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Microbead out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Microbead in simple terms?

Microbeads are manufactured solid plastic particles of less than one millimeter in their largest dimension. They are most frequently made of polyethylene but can be of other petrochemical plastics such as polypropylene and polystyrene.

Why does Microbead matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Microbead?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Microbead.

Tags

  • Cosmetics chemicals
  • Plastics industry

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